I was asking how you arrived at 9-10,000 RPM as a target? The rod-breaking stress level @ 10,000 RPM is double that @ 7,000 RPM.

Double the budget, much less power than stock stroke.
The whole "the heads will work much better with smaller displacement" has been tried by everyone in the last 80 years.
The heads will work very differently, but not necessarily better.

The rod ratio goes to hell. Unless you want a boat anchor for a piston, the rod gets longer by half the stroke change (more if low piston weight is desired):
6.86" ÷ 3.75" = 1.83:1 ratio
7.11" (+ .25" longer rod) ÷ 3.25" = 2.19:1 ratio
Do you know what that does to vacuum? To air motion around overlap?

You're throwing 50 years of hemi cam development over the cliff, and starting with a blank sheet of paper.

Ask Barton for the price on a complete set of rockers (take a stiff drink 1st).